Growth differentiation factor 15 (GDF15) is a protein belonging to the transforming growth factor beta (TGF-β) superfamily. GDF15 is also known as TGF-PL, MIC-1, PDF, PLAB, NAG-1, and PTGFB. GDF15 mRNA is reported to be most abundant in the liver, with lower levels seen in some other tissues. Its expression in liver can be significantly up-regulated in injury of organs such as liver, kidney, heart and lung.
GDF15 is reported to play a role in regulating inflammatory and apoptotic pathways in injured tissues and during disease processes. It has been reported that GDF15 is a mediator of cachexia in various diseases. However, cachexia is a complex and incompletely understood syndrome. In addition, at least some tumors over-express and secrete GDF15, and elevated serum GDF15 levels have been associated with various cancers. GDF-15 has been described as a negative regulator of macrophage activation by suppressing the release of TNF-α, IL-1, IL-2 and MCS-F, thus inhibiting the positive feedback of local inflammatory signaling similar to the effects of TGF-β. Monoclonal antibodies against GDF15 have been disclosed as potential therapeutic agents for the treatment of cachexia and of cancer. The receptor for GDF15 is unknown.
There is a significant unmet need for therapeutic agents effective to treat weight loss associated with a number of diseases and conditions, including wasting diseases such as cachexia or sarcopenia and inflammatory conditions such as systemic inflammation or an acute inflammatory response. There is also a significant unmet need for therapeutic agents effective to treat chronic diseases, including cancer, chronic renal disease, chronic obstructive pulmonary disease, AIDS, tuberculosis, chronic inflammatory disease, systemic inflammation, and muscle wasting diseases, including in which involuntary body weight loss and/or muscle mass loss is involved.